A Case of Concurrent MPO-/PR3-Negative ANCA-Associated Glomerulonephritis and Membranous Glomerulopathy.

Yasuyuki Nakada,Yoriko Hara,Hiraku Yoshida,Takashi Yokoo,Yoshihiro Arimura,Nobuo Tsuboi,Yasuto Takahashi,Hideo Okonogi,Tetsuya Kawamura

doi:10.1155/2015/316863

Abstract

We report a case in which antineutrophil cytoplasmic antibody- (ANCA-) associated glomerulonephritis and membranous glomerulopathy (MGN) were detected concurrently. The patient showed rapidly progressive renal deterioration. A renal biopsy showed crescentic glomerulonephritis, together with marked thickening and spike and bubbling formations in the glomerular basement membranes. Indirect immunofluorescence examination of the patient's neutrophils showed a perinuclear pattern. Enzyme-linked immunosorbent assays revealed that the ANCA in this case did not target myeloperoxidase (MPO) or proteinase 3 (PR3) but bactericidal-/permeability-increasing protein, elastase, and lysosome. The relationship between these two etiologically distinct entities, MPO-/PR3-negative ANCA-associated glomerulonephritis and MGN, remains unclear.

Highlights

The presence of antineutrophil cytoplasmic antibody (ANCA) in serum may be associated with small-vessel vasculitis, which occurs often in the renal glomeruli
The pathological and physiological roles of ANCA to minor antigens, other than proteinase 3 (PR3) and MPO, have not been determined, but some cases have been reported in relation to systemic vasculitis
Wiesner et al reported that human neutrophil elastase antibodies (HNEANCA) are often found in cocaine-induced midline destructive lesions [5]

Summary

Introduction

The presence of antineutrophil cytoplasmic antibody (ANCA) in serum may be associated with small-vessel vasculitis, which occurs often in the renal glomeruli. The two major antigens for ANCA, proteinase 3 (PR3) and myeloperoxidase (MPO), are usually referred to as the serological markers of ANCA-associated vasculitis and glomerulonephritis on ELISA tests, with perinuclear and cytoplasmic lesions in neutrophils, respectively. In these diseases, it is well-known that pauci-immune necrotizing and/or crescentic glomerulonephritis are often found in renal biopsies, with nonnephrotic range proteinuria and relatively high degrees of hematuria, as well as rapid decreases in kidney function, leading to end-stage renal disease (ESRD) within several months. No case of MPO- and PR3-negative ANCA-GN concurrent with MGN has been reported previously [4]

Case Report

Discussion

Findings

Conflict of Interests